1. Field of the Invention
The present invention relates to a board connector that is mounted on a printed circuit board (PCB).
2. Description of the Related Art
In general, a board connector is mounted in a connector housing having a hood portion by inserting terminals into the connector housing. In the board connector, connection ends of the terminals between the terminals and terminals of a counterpart connector protrude to the hood portion, and connection ends of the terminals between the terminals and a printed circuit board are bent in an L shape so as to protrude the connection ends to a side opposite to the hood portion. In this case, the connector housing is used to hold the terminals, maintain a fitting state between the board connector and the counterpart connector, and to fix the board connector to the printed circuit board. Further, the terminals are used to be electrically connected to the terminals of the counterpart connector, to fix the board connector to the printed circuit board by soldering between the terminals and the printed circuit board, and to be electrically connected to a circuit of the printed circuit board.
This type of board connector fixes terminals protruding from a wall surface of the connector housing to the outside to the printed circuit board by means of soldering, but in this case, the support is insufficient. Accordingly, a means for fixing the connector housing to the printed circuit board is generally provided.
As an example of the board connector according to the related art, a board connector shown in FIG. 4 is known (for example, Patent Document 1).
A board connector 100 shown in FIG. 4 has a connector housing 110 and a plurality of terminals 115 that are disposed in the connector housing 110. A metal coating film 120 is provided on a bottom surface of the connector housing 110 and functions as a fixing means for soldering so as to fix the board connector 100 to a printed circuit board (not shown).
The connector housing 110 is formed in substantially a rectangular shape using a synthetic resin, and has its front surface that is provided with a fitting recess 110A into which a counterpart connector is fitted. Each of the terminals 115 is formed of a conductive material, and has one end that is provided with a contact portion 115a and the other end that is provided with a soldering portion 115b. The contact portion 115a is located in the fitting recess of the connector housing and comes into contact with the counterpart connector, and the soldering portion 115b protrudes from a rear surface of the connector housing 110 and soldered on the printed circuit board.
In order to mount the board connector 100 having the above-described structure in the printed circuit board, the soldering portions 115b of the terminals 115 and the metal coating film 120 overlap pads (not shown) that are formed on the printed circuit board. Then, a reflow process is performed to melt soldering paste (not shown) applied to the pads in advance so as to solder the soldering portions 115b of the terminals 115 and the metal coating film 120 to the pads of the printed circuit board.
As such, if the connector housing 110 is directly soldered on the printed circuit board, external force applied to the terminals 115 can be dispersed into the terminals 115 and the connector housing 110. For this reason, it is possible to improve mounting strength of the terminals 115 to the printed circuit board, which achieves secure electrical connection between the terminals 115 and the printed circuit board.
Further, as examples of different types of board connectors, board connectors that are disclosed in Patent Documents 2, 3, and 4 have been known. In these board connectors, L-shaped metal fittings are individually press-fitted into left and right ends of a connector housing that constitutes a connector main body, and each of the metal fittings is soldered on the printed circuit board, such that the connector main body is fixed on the printed circuit board.
Meanwhile, according to a technology disclosed in Patent Document 1 that corresponds to a structure shown in FIG. 4, when a metal coating film 120 is provided on a bottom surface of the connector housing 110 and soldered on the printed circuit board, shearing force is applied to the soldering portions in a board surface direction due to the difference in thermal expansion between the printed circuit board and the connector housing 110, or force is applied to the soldering portion in a film removing direction because of warpage of the printed circuit board due to the thermal change over time, which may cause solder cracks.
Further, according to technologies disclosed in Patent Documents 2, 3, and 4, when the L-shaped metal fittings are individually press-fitted into the left and right ends of the connector housing and are soldered on the printed circuit board, if the length of the board connector in a left-to-right direction is increased, it is not possible to prevent warping of the connector housing. As a result, excessively strong force may be easily applied to a soldering portion of the connector terminal to the printed circuit board or connection portions between the terminals in the board connector.
Patent Document 1:JP-UM-A-6-84680
Patent Document 2:JP-A-2005-166491
Patent Document 3:JP-A-2005-294163
Patent Document 4:JP-A-2005-302523